"Stopping Power"...myth or reality?
- Thread starter Troy26
- Start date
- Status
LeonCarr
Member
There is no such thing as the Sword Excalibur in a handgun. Use the various stopping power articles, shot placement articles, and ammunition recommendations as a guide, not as gospel. "Stopping Power" involves a myriad of variables related to internal ballistics (what happens inside the firearm and inside the cartridge), external ballistics (what happens once the bullet leaves the barrel), terminal ballistics (what happens when the bullet strikes the target and where it strikes the target, vital areas, etc), and also the condition of the target/bad guy(size, weight, pain tolerance, chemical dependency, mindset, and a long list of other human related stuff).
I use the 3F method. Fire til the Felon Falls.
Also, using the search function will yield a buttload of information/threads/posts on the subject.
Just my .02,
LeonCarr
I use the 3F method. Fire til the Felon Falls.
Also, using the search function will yield a buttload of information/threads/posts on the subject.
Just my .02,
LeonCarr
Trying to quantify the relative "stopping power" of one cartridge vs. another is folly. A bigger hole will incapacitate quicker if put in the same place, but no one can fire all calibers with equal proficiency. Use the most powerful caliber you can fire quickly and accurately. A .22 in the heart beats a .45 in the hand. A .45 in the heart beats both, but that's only going to happen if you can handle the .45 to begin with.
R.W.Dale
Member
Hollywood myth, Think about it "for every action there is an oppisite but equal reaction" When you pull the trigger is the recoil enough to stop YOU. Nope didn't think so. So why would the same amount of energy going the other direction be any diffrent.
dmallind
Member
I've heard that explanation a lot, and true as it is is missing something. Every action has an equal and opposite reaction true, but not an equal and opposite RESULT.
Example. A well placed fist swung by a powerful man will knock over (and possibly out) another man of equal size, without causing any noticeable motion in the puncher. Why? because the force of the punch is applied to only a few square inches of the punchEE's nose, while all that "reaction" of the force of the impact the other way is applied throughout the entire body of the punchER. Yes I also know that there is already momentum in the original direction to overcome too. Simplifying, 'K?
Same thing is why stiletto heels on an average wome damage a floor more than an elephant - pressure is force divided by area. Same force over smaller area = greater pressure. Pressure can knock you over - anyone ever get pushed over in the playground by another kid? Did they fall over too at the same time (not when you got up and kicked their ass
).
So for gunfire, the force on the shootEE is applied to an even smaller area - usually a fraction of a square inch. The force on the shootER first has to overcome the resistance of the recoil spring, the weight of the gun, and is then absorbed (not the technical term I think, but you know what I mean) by the movement of the wrist and arm joints, before being applied over a whole lot of the body area of the shootER. Big difference.
Of course this does NOT mean .45ACP rounds send people flying 8' in the air or spin them around like whirling dervishes, but it sure as hell applies more pressure to the shootee than the shooter.
Example. A well placed fist swung by a powerful man will knock over (and possibly out) another man of equal size, without causing any noticeable motion in the puncher. Why? because the force of the punch is applied to only a few square inches of the punchEE's nose, while all that "reaction" of the force of the impact the other way is applied throughout the entire body of the punchER. Yes I also know that there is already momentum in the original direction to overcome too. Simplifying, 'K?
Same thing is why stiletto heels on an average wome damage a floor more than an elephant - pressure is force divided by area. Same force over smaller area = greater pressure. Pressure can knock you over - anyone ever get pushed over in the playground by another kid? Did they fall over too at the same time (not when you got up and kicked their ass
).So for gunfire, the force on the shootEE is applied to an even smaller area - usually a fraction of a square inch. The force on the shootER first has to overcome the resistance of the recoil spring, the weight of the gun, and is then absorbed (not the technical term I think, but you know what I mean) by the movement of the wrist and arm joints, before being applied over a whole lot of the body area of the shootER. Big difference.
Of course this does NOT mean .45ACP rounds send people flying 8' in the air or spin them around like whirling dervishes, but it sure as hell applies more pressure to the shootee than the shooter.
RecoilRob
Member
Fact: Total energy delivered to the target is always less than that absorbed by the shooter. No way around it.
The results ARE different because of the disparity of area absorbing the energy. When concentrated on a 1/4 sq in of body, the flesh gives way and PENETRATION results. The destructive ability of bullets is due to the penetration and destruction of tissue.
Momentum and energy only determine the depth and amount of tissue that can be crushed.
No mystery. Pretty simple stuff. Poke a hole, make person feel bad. Hit hard without penetration, make person feel mad.
The results ARE different because of the disparity of area absorbing the energy. When concentrated on a 1/4 sq in of body, the flesh gives way and PENETRATION results. The destructive ability of bullets is due to the penetration and destruction of tissue.
Momentum and energy only determine the depth and amount of tissue that can be crushed.
No mystery. Pretty simple stuff. Poke a hole, make person feel bad. Hit hard without penetration, make person feel mad.
R.W.Dale
Member
TRUE but that means that at best handguns are little more than remote stabbing devices.
Newton's laws all deal with momentum and force, mostly. None of them has anything to do with energy.
"For every action, there is an equal but opposite reaction." That means that the shooter and shootee will absorb equal amounts of momentum, not energy. The recoil energy of most guns is well under 10 ft-lb.
Tissue damage is determined by stress, which is force divided by area. Energy is distance times force. Force is mass times acceleration. Momentum is mass times velocity.
So for instance, a gun with a 2 square inch backstrap and 5 ft-lbs of recoil (about right for a 40 oz. gun in .45 ACP) that moves 6 inches under recoil, exerts 5 pounds per square inch on your hand, on average.
5 ft-lbs / 0.5 feet = 10 lbs
10 lbs / 2 sq in. = 5 psi
A bullet that hits with 350 ft-lbs, expands to .7", and penetrates 13" (fairly average performance for a .45), exerts an average stress of about 840 pounds per square inch. Huge difference.
350 ft-lbs / (13/12) feet = 323 lbs
323 lbs / (pi * .35^2) in = 840 psi
"For every action, there is an equal but opposite reaction." That means that the shooter and shootee will absorb equal amounts of momentum, not energy. The recoil energy of most guns is well under 10 ft-lb.
Tissue damage is determined by stress, which is force divided by area. Energy is distance times force. Force is mass times acceleration. Momentum is mass times velocity.
So for instance, a gun with a 2 square inch backstrap and 5 ft-lbs of recoil (about right for a 40 oz. gun in .45 ACP) that moves 6 inches under recoil, exerts 5 pounds per square inch on your hand, on average.
5 ft-lbs / 0.5 feet = 10 lbs
10 lbs / 2 sq in. = 5 psi
A bullet that hits with 350 ft-lbs, expands to .7", and penetrates 13" (fairly average performance for a .45), exerts an average stress of about 840 pounds per square inch. Huge difference.
350 ft-lbs / (13/12) feet = 323 lbs
323 lbs / (pi * .35^2) in = 840 psi
Any firearm of any caliber can stop an assailant. There's none of them that will pick up and throw the person 10' like shown in the movies. The only thing that does that is artillery. Even rifles won't knock someone backwards, just look at any actual war footage that shows men being hit and dropping.
An assailant will stop their attack for many reasons, not all of which is due to the power of the gun or the ammunition. In many cases the attacker stops simply because they choose to do so either to avoid further injury or a psychological reaction to being shot.
There are only 3 physical reasons that make an attacker stop:
1. Nervous system disruption.
2. Skeletal support destruction.
3. Circulatory or oxygenation collapse.
1 and 2 need accurate placement or just good luck.
2 and 3 are more likely or at least quicker with larger caliber weapons.
An assailant will stop their attack for many reasons, not all of which is due to the power of the gun or the ammunition. In many cases the attacker stops simply because they choose to do so either to avoid further injury or a psychological reaction to being shot.
There are only 3 physical reasons that make an attacker stop:
1. Nervous system disruption.
2. Skeletal support destruction.
3. Circulatory or oxygenation collapse.
1 and 2 need accurate placement or just good luck.
2 and 3 are more likely or at least quicker with larger caliber weapons.
RecoilRob
Member
Krochus: "remote stabbing device" Well put! If people got the 'energy dump syndrome' out of their heads and viewed the handgun as a way of remotely poking a hole into something, I believe they would be better served when choosing a weapon for self defense. Hydrostatic shock effects (that ARE real in rifles) don't happen with most handguns and are best not thought of.
RyanM: My comments regarding energy were assuming that ALL forms of force are energy, regardless of whether they are kinetic, momentum, or whatever. Perhaps I mispoke lumping the terms together in a generalization. Sorry.
But, the generalization still holds. The shooter has absorbed more FORCE than the projectile can deliver to the target because it loses some of its' energy (speed, momentum..whatever) to heat via friction to the air.
Total accumulation of all forces is applied less to the target. The only reason damage is done is because of the focusing of the remaining force on a small area.....which gives way.
If a bullet resistant vest is worn and stops the penetration of the round, little damage is done (besides maybe some localised bruising) despite the fact that the target just absorbed ALL of the energy (momentum, velocity, force et. al.).
I read, re-read and re-re-read your math and am concluding that you agree that the target absorbs less total force than the shooter, just that it is concentrated on a smaller area. Yes?
RyanM: My comments regarding energy were assuming that ALL forms of force are energy, regardless of whether they are kinetic, momentum, or whatever. Perhaps I mispoke lumping the terms together in a generalization. Sorry.
But, the generalization still holds. The shooter has absorbed more FORCE than the projectile can deliver to the target because it loses some of its' energy (speed, momentum..whatever) to heat via friction to the air.
Total accumulation of all forces is applied less to the target. The only reason damage is done is because of the focusing of the remaining force on a small area.....which gives way.
If a bullet resistant vest is worn and stops the penetration of the round, little damage is done (besides maybe some localised bruising) despite the fact that the target just absorbed ALL of the energy (momentum, velocity, force et. al.).
I read, re-read and re-re-read your math and am concluding that you agree that the target absorbs less total force than the shooter, just that it is concentrated on a smaller area. Yes?
No, force is not equal between the shooter and shootee. Neither is energy. Only momentum.
Momentum isn't a "form of energy." Energy may as well be totally irrelevant. Kinetic energy is just force * distance, and all of the bullet's kinetic energy is turned into heat energy within a fraction of a second of the bullet coming to rest. Momentum, on the other hand, is transferred into the target, accelerating it a bit (not even enough to affect balance, of course). That's how physics works. 100% of the kinetic energy is turned into heat, and 100% of the momentum is conserved as momentum.
In the example given, the shooter gets hit with about 10 pounds of force, while the shootee gets 323 pounds. That's because of the enormous velocity difference between the gun and the bullet. The momentums are equal, but the forces, energies, and stresses are not.
There are a bunch of ways of figuring out the average force and stress, but using energy is the easiest.
Let's say you're shooting a 5" 1911. Within 5" (more like 4.5" really), the bullet is accelerated from 0 fps to let's say 828 fps, for 350 ft-lbs. 1 ft-lb is 1 pound of force over 1 foot of distance. 5" is 5/12 feet, so that's 840 pounds of force on the bullet. Bullet diameter is .451", so that's 5258 PSI on the bullet, on average.
Then the rest is the same.
Shooter: 10 lbs, 5 PSI
Shootee: 323 lbs, 840 PSI
Bullet: 840 lbs, 5258 PSI
(The fact that the PSI in the shootee and the force on the bullet are the same is just a coincidence.)
I'd say the bullet is getting the short end of the stick.
Remember, if we forget about air resistance, then the momentum of the bullet in flight, the momentum of the shooter and gun after firing, and the momentum of the shootee and bullet after getting hit, are all equal. Even though the forces are extremely different.
Also, high force or high stress does not correlate to high damage. The shallower the bullet penetrates, the higher the average force will be, because force = energy / distance (and also = mass * acceleration). So that means someone wearing a bulletproof vest will absorb a lot more force than someone with no armor.
Of course, this is all a gross oversimplification, especially reducing force to average force. In reality, in cases like this, force will be high at the start and gradually taper off (no, they don't start at the same number). Average force does give you something of an idea of the "real" force involved, though.
Oh, wait a minute, I did recoil wrong. It should be much higher. But still nowhere near what the bullet and shootee experience.
Momentum isn't a "form of energy." Energy may as well be totally irrelevant. Kinetic energy is just force * distance, and all of the bullet's kinetic energy is turned into heat energy within a fraction of a second of the bullet coming to rest. Momentum, on the other hand, is transferred into the target, accelerating it a bit (not even enough to affect balance, of course). That's how physics works. 100% of the kinetic energy is turned into heat, and 100% of the momentum is conserved as momentum.
In the example given, the shooter gets hit with about 10 pounds of force, while the shootee gets 323 pounds. That's because of the enormous velocity difference between the gun and the bullet. The momentums are equal, but the forces, energies, and stresses are not.
There are a bunch of ways of figuring out the average force and stress, but using energy is the easiest.
Let's say you're shooting a 5" 1911. Within 5" (more like 4.5" really), the bullet is accelerated from 0 fps to let's say 828 fps, for 350 ft-lbs. 1 ft-lb is 1 pound of force over 1 foot of distance. 5" is 5/12 feet, so that's 840 pounds of force on the bullet. Bullet diameter is .451", so that's 5258 PSI on the bullet, on average.
Then the rest is the same.
Shooter: 10 lbs, 5 PSI
Shootee: 323 lbs, 840 PSI
Bullet: 840 lbs, 5258 PSI
(The fact that the PSI in the shootee and the force on the bullet are the same is just a coincidence.)
I'd say the bullet is getting the short end of the stick.
Remember, if we forget about air resistance, then the momentum of the bullet in flight, the momentum of the shooter and gun after firing, and the momentum of the shootee and bullet after getting hit, are all equal. Even though the forces are extremely different.
Also, high force or high stress does not correlate to high damage. The shallower the bullet penetrates, the higher the average force will be, because force = energy / distance (and also = mass * acceleration). So that means someone wearing a bulletproof vest will absorb a lot more force than someone with no armor.
Of course, this is all a gross oversimplification, especially reducing force to average force. In reality, in cases like this, force will be high at the start and gradually taper off (no, they don't start at the same number). Average force does give you something of an idea of the "real" force involved, though.
Oh, wait a minute, I did recoil wrong. It should be much higher. But still nowhere near what the bullet and shootee experience.
Stopping power is reality in the sense that it is POSSIBLE to stop a person with a handgun most of the time.
Stopping power is a myth in the sense that most of what makes it likely that a person will stop has to do with things OTHER than the characteristics of the handgun or ammunition used.
So, you CAN stop a person with a handgun, but if you do, it's not simply a matter of what kind of handgun, what caliber, or what ammo you chose.
Stopping power is a myth in the sense that most of what makes it likely that a person will stop has to do with things OTHER than the characteristics of the handgun or ammunition used.
So, you CAN stop a person with a handgun, but if you do, it's not simply a matter of what kind of handgun, what caliber, or what ammo you chose.
Duramaximum
Member
They did this on Mythbusters and didn't knock the dead pig off the chain until they finally blasted it with a slugged shotgun, and even then it didn't "blow it back."
MCgunner
Member
Give me energy and I'll give him death. Speaking of death, this subject is about discussed to death.
MCgunner
Member
Okie dokey then, I'll leave the .45, the 9, and the .38 at home from now on and just rely on my NAA .22 mini and its 1" barrel, I mean if the gun and ammo don't matter....
...he said right before discussing the subject further.MCGunner said:
I didn't say that the gun and ammo don't matter.MCGunner said:
JohnKSa said:
All a handgun can do is poke a small hole. Even a large handgun still pokes a small hole. WHERE the hole is, the mindset of the person being shot, the chemical impairment/pain tolerance/physical conditioning of the person being shot, etc. all make more difference than the size or depth of the hole.JohnKSa said:
Any common handgun caliber is quite capable of killing or stopping a person instantly if the person using it is extremely skilled or very lucky, or if the person being shot is highly predisposed to quit immediately after being shot. As you go up the handgun power spectrum, it gets easier, but all the power in the world means very little if the user can't employ it properly or if the person being shot is extremely determined (and is not hit in the CNS).
- Status
Similar threads
- Locked
- Locked
